21012001211200 has 84 divisors (see below), whose sum is σ = 52001515445580. Its totient is φ = 8356217712640.

The previous prime is 21012001211171. The next prime is 21012001211209. The reversal of 21012001211200 is 211210021012.

It can be written as a sum of positive squares in 6 ways, for example, as 19329897024 + 20992671314176 = 139032^2 + 4581776^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012001211209) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 37678405 + ... + 38232004.

Almost surely, 2^{21012001211200} is an apocalyptic number.

21012001211200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21012001211200 is an abundant number, since it is smaller than the sum of its proper divisors (30989514234380).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21012001211200 is a wasteful number, since it uses less digits than its factorization.

21012001211200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75910604 (or 75910589 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21012001211200 its reverse (211210021012), we get a palindrome (21223211232212).

It can be divided in two parts, 2101200 and 1211200, that added together give a square (3312400 = 1820²).

The spelling of 21012001211200 in words is "twenty-one trillion, twelve billion, one million, two hundred eleven thousand, two hundred".